KR20210001342U - Nuclear Power Plant Installation Welding Device Using Low Temperature Coating Dispensing - Google Patents

Abstract

The present invention relates to a welding device for a nuclear power plant using a low-temperature coating spraying method, and more particularly, a hopper in which a coating agent is stored, a spray gun connected through the hopper and a connecting pipe and the coating agent is ejected through a spout; A gas supply pipe for supplying a high-pressure gas to the hopper so that the coating agent stored in the hopper is supplied to the spray gun through the connection pipe to be ejected, and a high-pressure to the spray gun so that the coating agent ejected from the spout is heated to a certain temperature It relates to a welding device for a nuclear power plant using a low-temperature coating spraying method, characterized in that it includes a heating gas supply pipe for heating and supplying gas.

Description

Welding device for nuclear power plant using low temperature coating spraying method {Nuclear Power Plant Installation Welding Device Using Low Temperature Coating Dispensing}

The present invention relates to a welding device for nuclear power plants using a low-temperature coating spraying method, and more specifically, primary water stress corrosion cracking (PWSCC) and stress corrosion cracking (SCC) and chloride stress corrosion cracking caused by welding in nuclear power plants ( CISCC) by coating the inner peripheral surface of the power plant with a low-temperature coating spraying method, it relates to a welding device for a nuclear power plant using a low-temperature coating spraying method.

For pressure vessels, pressurizers, reactors, canisters, nozzles or pipe connection parts used in nuclear power generation facilities, austenite stainless steel is used for chromium-molybdenum (Cr-Mo) heat-resistant steel, carbon steel, and Inconel alloy. SAW (Submerged Arc Welding) welding with the main component was used.

In general, SAW welding is a method of melting a welding material using welding heat, and welding the melted welding material to have excellent corrosion resistance on the surface of a product of a nuclear power plant.

However, in the case of a pressurized light water reactor (PWR) type nuclear power plant, water is used as a coolant, the primary system in which boiling water circulates in the reactor, and the secondary system in which the water that receives heat energy from the primary system turns into steam and turns the turbine. In the case of parts divided into systems and used in the primary system, sensitized zones occur because they are exposed to temperatures of 400 to 800 °C, and this zone is subjected to stress called Primary Water Stress Corrosion Cracking (PWSCC). Corrosion cracking (SCC) is highly likely to occur.

Here, stress corrosion cracking (SCC) refers to a phenomenon in which a material is destroyed by interaction with a corrosive environment when under stress action.

In addition, Chloride-Induced Stress Corrosion Cracking (CISCC), which is a stress corrosion cracking (SCC) caused by chloride occurring in and around the welding part of the canister of the spent nuclear fuel dry storage device, occurs in welding. was highlighted as

As described above, in the melting and fusion welding of SAW welding, various defects occur in the base material due to the heat of welding, and residual compressive stress remains, which is pointed out as one of the causes of corrosion cracking depending on the use cycle.

In addition, in order to prevent stress corrosion cracking such as stress corrosion cracking and chloride-induced stress corrosion cracking described above, the techniques of cavitaion peening and laser peening were used to prevent stress corrosion, but many attempts were made to prevent stress corrosion cracking. There is a problem in that it takes time and a lot of money to work.

A prior patent technology for welding the surface of a product of a nuclear power plant to have excellent corrosion resistance has been proposed. Korean Patent Publication No. 10-2001-0089170 of Prior Document 001 relates to a device for automatic welding of clad steel sheets, which performs welding of clad steel sheets with non-uniform clad widths, and utilizes high welding current to determine the amount of welding and welding. Disclosed is a "strip SAW automatic welding device" that can improve speed and secure welding quality.

However, according to Prior Document 001, even if the machine works by fusion welding, which melts the welding material by heating the product surface of a nuclear power plant with welding heat, residual stress due to heat effect remains in the base material, so corrosion cracking due to residual stress may occur. There is a problem that there is

In addition, when residual stress remains, the lifespan of the nuclear reactor and the intermediate storage device for spent nuclear fuel is shortened, so that there is a problem in that nuclear components may be released.

In addition, there is a problem in that the residual stress remains in the base material due to the high temperature heat treatment during SAW welding, and the cladding thickness cannot be controlled, so that the welding surface is not uniformly processed.

(Prior Document 001) Republic of Korea Patent Publication No. 2003-0058646 (2003.07.07.)

The problem to be solved by the present invention is to provide a welding device for a nuclear power plant using a low-temperature coating spraying method that can prevent high-temperature cracking due to melt welding and welding defects due to residual stress.

Another problem to be solved by the present invention is nuclear power generation using a low-temperature coating spraying method that prevents corrosion due to residual stress that occurs when the inner peripheral surface of a nuclear power plant is welded by coating the surface of a base material with powder of a metal component with a high-pressure gas. It is to provide welding equipment for equipment.

Another problem to be solved by the present invention is to provide a welding equipment for nuclear power generation facilities using a low-temperature coating spraying method that reduces production costs by replacing expensive cavitation peening and laser peening.

In order to achieve the above technical problem, the present invention has a hopper in which the coating agent is stored, a spray gun that is connected through the hopper and the connector and the coating agent is ejected through the spout, and the coating agent stored in the hopper is connected to the connector. A gas supply pipe for supplying high-pressure gas to the hopper so that it is supplied to the spray gun through the jetting port, and a heating gas supply pipe for heating and supplying the high-pressure gas to the spray gun so that the coating agent jetted from the jetting port is heated to a predetermined temperature. We propose a welding device for nuclear power plant using a low-temperature coating spraying method, characterized in that.

The coating agent may include at least one metal among carbon steel, stainless steel, nickel alloy, copper, and titanium alloy is used.

The coating agent may further include a powder form.

The heating gas supply pipe may include a heater for heating the high-pressure gas.

The heater may include heating a high-pressure gas to 150 to 850° C. so that the powder-type coating agent can be coated on the base material.

According to the embodiments of the present invention, by coating the metal powder on the inner peripheral surface of the nuclear power plant with a high-pressure gas, the speed at which the high-pressure gas is ejected and the powder impact on the inner peripheral surface are peened, thereby minimizing the residual stress generated in the fusion welding can

According to the embodiments of the present invention, corrosion cracking due to residual stress in the heat-affected zone can be prevented when the metal powder is laminated on the nuclear power plant when fusion welding is performed.

According to embodiments of the present invention, a cladding can be designed with a predetermined thickness by spraying a plurality of metal powders and stacking the metal powders.

According to the embodiments of the present invention, cracking due to residual stress on the surface of the base material can be prevented by spraying a coating agent for high-temperature cracks that inevitably occur on the surface of the base material that forms high-temperature welding even when welding with a welding machine.

1 is a side view showing a welding device for a nuclear power plant using a low-temperature coating spraying method according to an embodiment of the present invention.
Figure 2 is a block diagram of a spray flow of a low-temperature coating spraying device according to an embodiment of the present invention.
3 is a side view of the shape of the coating layer according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be

On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, process, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that this does not preclude the existence or addition of numbers, processes, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

The terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor may properly define the concept of the term in order to best describe his invention. Based on the principle that there is, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

In addition, if there is no other definition in the technical terms and scientific terms used, it has the meaning commonly understood by those of ordinary skill in the art to which this invention belongs, and the summary of the present invention in the following description and accompanying drawings Descriptions of known functions and configurations that may be unnecessarily obscure will be omitted.

The drawings introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms. Also, like reference numerals refer to like elements throughout. It should be noted that the same components in the drawings are denoted by the same reference numerals wherever possible.

Hereinafter, it will be described in detail with reference to the accompanying drawings in this specification.

1 is a side view showing a welding device for a nuclear power plant using a low-temperature coating spraying method according to an embodiment of the present invention.

As shown in FIG. 1, the hopper 220 in which the coating agent 260 is stored, and the hopper 220 and the spray gun are connected through the connector 221 and the coating agent 260 is ejected through the spout 250 ( 240) and the coating agent 260 stored in the hopper 220 is supplied to the spray gun 240 through the connection pipe 221 to be ejected. A gas supply pipe for supplying high-pressure gas to the hopper 220 It may include a 211 and a heating gas supply pipe 231 for heating and supplying high-pressure gas to the spray gun 240 so that the coating agent 260 ejected through the spout 250 is heated to a predetermined temperature.

A gas supply unit 210 capable of supplying gas to one side of the low temperature coating injection device 200 is installed, and the hopper 220 and the heater 230 are connected to the gas supply branch 211 connected to the gas supply unit 210 . high-pressure gas is introduced into the

The high-pressure gas stored in the gas supply unit 210 is composed of at least one of nitrogen, helium, and air, and a plurality of gases may be mixed and used. The high-pressure gas is supplied to the hopper 220 and the heater 230 through the gas supply pipe 211 .

The hopper 220 is composed of a gas supply pipe 211 and a metal storage device (not shown) capable of storing metal powder. When high-pressure gas flows into the gas supply pipe 211, the metal powder stored in the metal storage device flows in. The high-pressure gas and the metal powder are mixed and transferred to the powder supply pipe 221 connected to one side of the hopper 220 .

The metal powder stored in the powder storage device (not shown) includes at least one metal powder of carbon steel, stainless steel, nickel alloy, copper, and titanium alloy, and the high pressure supplied to the gas supply unit 210 during low-temperature spray coating The gas is mixed with the metal powder and introduced into the spray gun 240 through the connection pipe 221 .

의 크기로 구성될 수 있으며 금속 분말에 세라믹 입자를 혼합해 사용할 수도 있다. 원자력 발전 설비의 부식 균열을 막기 위해서는 바람직하게는 금속 분말만 사용하는 것이 바람직하다.The particles of the metal powder are 1 to 45

It can be composed of a size of , and it can be used by mixing ceramic particles with metal powder. In order to prevent corrosion cracking of nuclear power plants, it is preferable to use only metal powder.

The heater 230 may heat the high-pressure gas at 150 to 850° C. so that the powder coating agent 260 can be coated on the welding part 100 . The heating gas heated to a predetermined temperature is introduced into the spray gun 240 through the heating gas supply pipe 231 .

In the spray gun 240 , a connection pipe 221 and a heating gas supply pipe 231 are inserted, a high-pressure gas and a metal powder are mixed and introduced through the connection pipe 221 , and a predetermined temperature is passed through the heating gas supply pipe 231 . The heating gas heated to the furnace is supplied, and the heating gas supply pipe 231 and the connection pipe 221 are connected to the inside of the spray gun 240 .

A jet port 250 is formed to one side of the spray gun 240 to jet the metal powder and heated gas, and the jet port 250 may be formed in a tapered shape in which the width is narrowed in the direction of the surface of the base material.

The spout 250 may be designed so that a certain portion of the width is narrowed in the longitudinal direction and then widened again. For example, when water flows out of the bottle due to the bottleneck phenomenon, the inner diameter of the neck portion of the bottle becomes narrower than the body of the bottle, so that the water does not overflow. Therefore, the heated gas and metal powder are introduced into the neck of the outlet 250, and at this time, the metal powder and the high-pressure gas are designed not to be excessively ejected, so that the cladding thickness can be adjusted when the coating layer is laminated.

Figure 2 is a block diagram of a spray flow of a low-temperature coating spraying device according to an embodiment of the present invention.

As shown in FIG. 2 , the gas supply unit 210 supplies high-pressure gas to the hopper 220 and the heater 230 through the gas supply pipe 211 , and after each process, the spray gun 240 through each supply pipe. It is introduced and mixed, and the coating agent 260 is ejected through the ejection port 250 connected to the longitudinal direction of the spray gun 240 to form the coating layer 300 on the welding part 100 .

It is preferable to work with the jet port 250 and the welding part 100 having a distance of 10 to 70 mm. In some cases, the distance may be adjusted according to the discharged flow rate.

In addition, the spout 250 is tapered in the direction of the welding part 100 so that the coating agent can be coated on the inner peripheral surface of the welding part 100 such as a pressure vessel, a pressurizer, a reactor, a canister, a nozzle or a pipe connection part used in a nuclear power plant. Can be made. .

Taking the canister among the nuclear power generation facilities as an example, the canister serves to store waste after nuclear power use, and it is necessary to prevent waste leakage due to stress corrosion.

Care should be taken during the initial work on corrosion cracking. Therefore, when joining or welding the inside of the canister, the low-temperature coating agent is sprayed from the welding part 100 of the nuclear power plant to a narrow section having a diameter of 9.5 to 16 mm, a section having a diameter of 600 to 700 mm, and a section having a diameter of 50 to 100 mm The diameter and length of the jet port 250 can be adjusted so that the coating can be performed.

The diameter of the spout 250 may be 6 ~ 15mm, and the length may be 8 ~ 30mm so that the coating agent can be sprayed on the inner peripheral surface of the nuclear power plant.

The discharge pressure at the outlet 250 is set to 5 to 30 bar when the gas stored in the gas supply unit 210 is helium and 5 to 30 bar when the gas stored in the gas supply unit 210 is nitrogen. This is preferable. In addition, in the case of a mixed gas in which helium and nitrogen are mixed, it may be configured in a range of 5 to 25 bar.

3 is a side view of the shape of the coating layer according to an embodiment of the present invention.

As shown in FIG. 3 , the coating layer 300 may be formed by ejecting at least one metal powder of carbon steel, stainless steel, nickel alloy, copper, and titanium alloy.

와 20 ~44

또는 44

미만의 입자 크기로 코팅층(300)을 형성할 수도 있다. 이와 같이, 코팅층(300)을 형성함으로 부식 균열(PWSCC)과 응력 부식 균열(SCC) 및 염화물 응력 부식 균열(CISCC)을 방지할 수 있다.The size of metal powder ranges from 1 to 20

and 20-44

or 44

It is also possible to form the coating layer 300 with a particle size of less than. In this way, by forming the coating layer 300, it is possible to prevent corrosion cracking (PWSCC), stress corrosion cracking (SCC), and chloride stress corrosion cracking (CISCC).

In order to prevent the primary water stress of the welding part 100 due to residual stress due to heat generated during the melting and fusion welding, the injection flow rate of the coating agent 260 may be set to 5 to 50 g/min. The amount of the coating layer 300 may be adjusted according to the injection flow rate, and the thickness of the cladding due to melt welding may be reduced and designed.

Those of ordinary skill in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential features thereof.

Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims to be described later rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents are interpreted as being included in the scope of the present invention. should be

In addition, it is of course possible to implement various modifications without departing from the gist of the present invention claimed in the claims as well as the various scope of application.

100: welding part 200: low-temperature coating spraying device
210: gas supply 211: gas supply pipe
220: hopper 221: connector
230: heater 231: heating gas supply pipe
240: spray gun 250: spout
260: coating agent 300: coating layer

Claims (5)

a hopper in which the coating agent is stored;
a spray gun connected through the hopper and the connecting pipe and the coating agent is ejected through the spout;
A gas supply pipe for supplying a high-pressure gas to the hopper so that the coating agent stored in the hopper is supplied to the spray gun through the connection pipe and ejected;
A welding device for a nuclear power plant using a low-temperature coating spraying method, characterized in that it comprises a heating gas supply pipe for heating and supplying a high-pressure gas to the spray gun so that the coating agent ejected from the spout is heated to a predetermined temperature. According to claim 1,
The coating agent is a welding device for a nuclear power plant using a low-temperature coating spraying method, characterized in that it is composed of at least one metal among carbon steel, stainless steel, nickel alloy, copper, and titanium alloy. 3. The method of claim 2,
The coating agent is a welding device for a nuclear power plant using a low-temperature coating spraying method, characterized in that in the form of a powder. According to claim 1,
The heating gas supply pipe is a welding device for a nuclear power plant using a low-temperature coating injection method comprising a heater for heating the high-pressure gas. 5. The method of claim 4,
The heater is a welding device for a nuclear power plant using a low-temperature coating injection method comprising heating the high-pressure gas to 150 ~ 850 ℃.

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